Answer:
Work done, W = −287500 Joules
Explanation:
It is given that,
Mass of the car, m = 920 kg
The car is travelling at a speed of, u = 90 km/h = 25 m/s
We need to find the amount of work must be done to stop this car. The final velocity of the car, v = 0
Work done is also defined as the change in kinetic energy of an object i.e.
[tex]W=\Delta K[/tex]
[tex]W=\dfrac{1}{2}m(v^2-u^2)[/tex]
[tex]W=\dfrac{1}{2}\times 920\ kg(0-(25\ m/s)^2)[/tex]
W = −287500 Joules
Negative sign shows the work done is done is opposite direction.
